There are certainly differences between doctrines.
I would have to check to see about canons and councils regarding asking intercession of the Saints. What I do know is that the Church approves it, and we cannot say that we know better than the Church and they are wrong. However, it is never a requirement for anyone to ask intercessions from any of the Saints. It is possible to be Orthodox and have reservations about it, and so avoid the practice, but it is also necessary to accept that the Church has reasons for what they teach and it's ok if we don't understand that - we just can't condemn the Church's teachings and set our own opinions above it. That's more an Orthodox mindset/phronema than anything dogmatic though.
Communion has always been reserved only for those baptized into the Church. And because of unfortunate schisms which exist within Christianity, today that means one has to be united Sacramentally with the Church (in this case EO) to receive the Eucharist. And it is set forth what form that takes and how it is prepared - bread and water+wine. These have deep theological meanings and cannot be substituted at our whim. (Though I have heard of priests in prison preparing a type of communion using what they had available - just as it is possible in an emergency situation to baptize a person by pouring sand on them if water is absolutely unavailable. This is written in the Didache.)
One of the major tenants of Orthodoxy is that the faith as we have received it from the Apostles must not be altered or changed. Protestants would have no such luxury because they basically came about in attempts to reform Catholicism, and so they are based on change. But I am also sure that essentially all Protestants seek to return to the early Church, and base whatever they do on how they interpret that to be.
But that means that the actual ways in which we (Orthodox) "do Church" cannot be compromised or changed. So we could not accept such variations, no.
But at the same we have a great freedom of belief in many things. It has been described as the Church being like a large fenced pasture. The fences are the borders - dogmas and such - that we cannot go beyond. But within those borders we have complete freedom to move about at will. Actually without knowing exactly what parts fit where, that's probably a terrible analogy for me to share, lol. But I can't think of a better one.